World 8-Castle

When the level begins you’ll see a blue P Switch guarded by a pair of Magikoopas. Dodge their attacks and stamp on the button to make a grated path rise out of the level, which will bridge the gap to the next platform. Continue forward, avoiding the various enemies along the way, and you'll come to a pair of poles next to each other. Make your way up the first pole, then jump to the second pole and climb up to the area above. Lava geysers will surround the second pole, so jump carefully.

Star Medal 1: When you come to a pair of poles next to each other, you can see a Star Medal near the base of the second one. Simply climb down and grab it, then climb back up quickly.

Up here, it will look like you can go to the right here, but this leads to a dead end. Instead, avoid the fire wheel that spins at the center of the platform and make for the rear wall. Jump on the ledges sticking out of the wall and move right, to the Arrow Platform. Ride the platform all way to the right, avoiding Magmaarghs, and you’ll come to the Checkpoint Flag.

Just beyond the Checkpoint Flag is a P Switch; Step on it and the platform will shoot up to the area above, where you’ll be attacked by a trio of Boomerang Bros. Defeat them to get a Boomerang Flower.

Star Medal 2: After the checkpoint you’ll come to a trio of Boomerang Bros. Behind them, between two platforms and suspended above some lava, is a Star Medal. You can get it with a Wall Jump if you're extremely careful, but it's much easier to defeat the three Boomerang Bros. to get a Boomerang Flower, then use that to get the Star Medal.

Past the Boomerang Bros you’ll come to a ledge overlooking some lava. As you near the ledge, some purple platforms will appear. Move across the appearing platforms and you'll come to an Exclamation Point Warp Block, which will teleport you to the next area.

As soon as you arrive in the next part of the level, Bowser will appear. Heading forward you’ll come to a section of lava bridged by rounded spinning platforms. Move across these, being careful not to fall in the lava.

Star Medal 3: After Bowser appears you’ll cross a series of round, spinning platforms. The third Star Medal is floating over some lava near the end of these platforms. Toss a boomerang at it, or use a Tanooki Suit to flutter to it.

When you reach Bowser, you won't be able to hurt him directly so focus on getting past him. He will be able to perform a slam attack, creating a shockwave that hurts you if you touch it. Run past Bowser and jump on the button to release the bridge and defeat him. After that, continue to the Flagpole, where a surprise waits for you.